HEAT STROKE AND HEAT EXHAUSTION
Introduction
Onset is sudden. This condition occurs a result of an excessive rise in the body temperature. When sweating and its evaporation are adequate the thermal loss maintain the the thermal balance of the body and continue to do so until the replenishment of water is maintained. The regulatory mechanism may fail if the conditions are adverse such as any deficiency of any water in the body or the internal requirement is excessive or the external conditions are unbearable under intense solar radiation, high temperature or very hot winds. The heat load imposed upon the body by such severe conditions may be about 200 kilo-calories per sq.meter of the body surface per hour, which is equivalent to the metabolic out put of any Strenuous work. It occurs due to lack of sweating and beak down of heat regulating centre in the brain. Under all such conditions, when the heat regulating mechanism fails to keep body temperature below the critical level, high fever develops. There may be sign of lack of sweating, giddiness, feeling vomiting, exhaustion and frequency of difficult pass urine. The individual in good health may suddenly become unconscious and get rapid rise in temperature above 40 degree Centigrade.The main causes are very high fever, stop sweating, head ache, restlessness, thirsty, anxiety, dry tongue, and in later stage unconsciousness with circulatory failure. the face is congested or in bluish colour, eyes are suffused, and the skin is dry and burning. abnormal and loss of consciousness occur in about one third cases. Mental confusion is seen in two third cases. Mortality varies with the degree of high fever/pyrexia
Heat exhaustion.
This occurs commonly more than heatstroke. Onset is gradual and body temperature does not rise as high as in the case of heat stroke. Those are not so much due to excessive temperature, but are rather the result of water and salt shortage due to excessive sweating. The reasons are depletion of salts in the body due to more sweating, and very high humidity and lack of cooling body. Water necessity in the body in hot climate is higher than in cold climate or a temperate climate. If water intake also reduced its exertion is reduced, but normal water loss necessary to remove the toxic nitrogenous metabolites has to continue in concentrated urine. Excessive sweating also reduces salt balance in the body. Normally 15 gm salts intake is adequate. Any salt consumed in excess over daily requirement is exerted in urine. If the intake is reduced or exertion in sweat is increased, salt is conserved by diminishing its excretion in the urine.
Water constitutes 70 percent of the body weight and maintenance of the fluid balance and its distribution in the 3 compartments is importance for the health of cells and tissues and its constant by the relative osmotic pressures.
Sign and symptoms of heat stroke
Temperature of body becomes above 104 degree F, dry skin, mental irritability, head ache, muscular cramps, fits, slow respiration and unconsciousness
The prevention of effects of heat.
The fluid intake must be enough to produce sweat and compensate for loss of water. Supply of cool water should be ensured. water consumption is likely to be inadequate and if it is not cool enough to quench thirst. Moderate work in hot climate may need upto 7 to 10 liters of water per day per and men for man on long time doing strenuous physical work even upto 15 liters a day may be needed.
Salt intake must compensate for its excessive loss in sweating. Rest and sleep should be adequate as the recovery must compensate for the activity. he best period for the best satisfactory and result restful sleep is during the coolest 3 to 4 hrs before dawn.
Bathing should be done every day. Improved shower baths are also of great important and valuable. An active , healthy and clean skin is an important factor dissipation of heat through radiation and evaporation and convection.
Clothing should be normally light and loose and permeable to water vapour and air. Food must be wholesome and well cooked and must be consumed with good amount of fluid. Dining hall should be cool and comfortable as no one can be expected to take full meals under hot and humid conditions.
Living rooms must be well ventilated and cool. A large numbers of heat stroke cases occurs in congested and ill ventilated and crowded rooms and huts, etc. In an area if possible, fans made be available to workers in their tents and quarters and no one should be allowed to sleep out side.
Medical inspection should be regular and through to detect early symptoms of the heat effect or any other diseases which may aggravate the effects of heat. Cases detected early can be often placed in rest in a cool place.
Avoid working in sun when it is too hot from 1 p m to 3 pm(IST) and drink plenty of pure water and use umber la while walking in sun, also avoid tea,coffee and alcohol,etc. during extreme summer and take rest or avoid doing strenuous work during peak hours.
First aid and early treatment
Keep the patient in bed or on the floor and fan on to reduce temperature. Raise the foot end and keep wet cloths on the body to reduce temperature and give plenty of fluid diet. This is necessary to stop the progress of illness, avoid permanent neurological injury and save life. Temperature must be reduced rapidly by spraying cool water and fanning. Ice-cool water is not to be used. Give plenty of cool water to drink, not too much. The temperature is checked every 10 minutes when cooling is reduced when it comes to 39 degree centigrade, patient is to be removed to the heat stroke centre. Dehydration is treated by administration of fluids and electrolytes. Cases of pure water loss is treated with water only. In severe cases with considerable impairment of mental and physical capacity there may be a deficit of 5 to 10 liters. In salt deficiency, if there is any giddiness and fainting on standing, there may be an approximate deficit of 4liters isotonic saline and if urinary chlorides are absent and if there is any feeling of vomiting/anorexia, nausea and vomiting with systolic blood pressure above 90mm of mercury, there may be a deficit of 5 liters, and if systolic blood pressure is less than 90mm of mercury, there is an approximate deficit of 8 liters.
Introduction
The effects of heat are spread out in the subtropics in the hot season. But hey are less happened in the tropics than generally, expected mainly the heat stroke. The epicenters for effects of heat are the shores of the Persian gulf and the central and western plains of India like Punjab, Hariyana, etc. The incidence of effects of heat in India is commonest in an area drawn horizontally through Nagpur with its western limit marked by drawn vertically along the western border of Bengal Asansol, excluding the coastal areas. The great majority of cases occur in Punjab, but there is hardly a place in the plains of northern and central India. Most cases occur during the week or two prior to the on set of the south west monsoon and during the breaks of monsoons, when atmospheric temperature and humidity are very high. In the north and west dangerous period is in the end of the June or later. In central India it is in mid-June. While in the south and eastern India, May and early June are critical periods. But the cases occur at any time during the hot weather in any part of India. The incidence in Kerala in recent years with sun burns starts from March to May before onset of monsoon.
Primary environmental factors
High atmospheric temperature is the most main important primary cause. Final effect is determined by the period of exposure to the hot temperature to 43 degree centigrade in dry atmosphere. As the temperature increases high 46 degree or more in the presence of wind velocity of more than 32 km per hour the danger point approaches and the heat stroke may occur. Direct exposure to sun rays increases the body heat load further and may occur the attack. Constant exposure to the sun glare is irritating to the causing point of distress, head ache, mental irritability and exhaustion. High atmospheric humidity is an important factor as high atmospheric temperature in the causation of heat effects, since upon it depends the evaporating power of the atmosphere and hence the body heat loss. Air movement is the important atmospheric factor which decides the human thermal comfort.
Heat stroke.
Heat stroke.
Onset is sudden. This condition occurs a result of an excessive rise in the body temperature. When sweating and its evaporation are adequate the thermal loss maintain the the thermal balance of the body and continue to do so until the replenishment of water is maintained. The regulatory mechanism may fail if the conditions are adverse such as any deficiency of any water in the body or the internal requirement is excessive or the external conditions are unbearable under intense solar radiation, high temperature or very hot winds. The heat load imposed upon the body by such severe conditions may be about 200 kilo-calories per sq.meter of the body surface per hour, which is equivalent to the metabolic out put of any Strenuous work. It occurs due to lack of sweating and beak down of heat regulating centre in the brain. Under all such conditions, when the heat regulating mechanism fails to keep body temperature below the critical level, high fever develops. There may be sign of lack of sweating, giddiness, feeling vomiting, exhaustion and frequency of difficult pass urine. The individual in good health may suddenly become unconscious and get rapid rise in temperature above 40 degree Centigrade.The main causes are very high fever, stop sweating, head ache, restlessness, thirsty, anxiety, dry tongue, and in later stage unconsciousness with circulatory failure. the face is congested or in bluish colour, eyes are suffused, and the skin is dry and burning. abnormal and loss of consciousness occur in about one third cases. Mental confusion is seen in two third cases. Mortality varies with the degree of high fever/pyrexia
Heat exhaustion.
This occurs commonly more than heatstroke. Onset is gradual and body temperature does not rise as high as in the case of heat stroke. Those are not so much due to excessive temperature, but are rather the result of water and salt shortage due to excessive sweating. The reasons are depletion of salts in the body due to more sweating, and very high humidity and lack of cooling body. Water necessity in the body in hot climate is higher than in cold climate or a temperate climate. If water intake also reduced its exertion is reduced, but normal water loss necessary to remove the toxic nitrogenous metabolites has to continue in concentrated urine. Excessive sweating also reduces salt balance in the body. Normally 15 gm salts intake is adequate. Any salt consumed in excess over daily requirement is exerted in urine. If the intake is reduced or exertion in sweat is increased, salt is conserved by diminishing its excretion in the urine.
Water constitutes 70 percent of the body weight and maintenance of the fluid balance and its distribution in the 3 compartments is importance for the health of cells and tissues and its constant by the relative osmotic pressures.
Sign and symptoms of heat stroke
Temperature of body becomes above 104 degree F, dry skin, mental irritability, head ache, muscular cramps, fits, slow respiration and unconsciousness
The prevention of effects of heat.
The fluid intake must be enough to produce sweat and compensate for loss of water. Supply of cool water should be ensured. water consumption is likely to be inadequate and if it is not cool enough to quench thirst. Moderate work in hot climate may need upto 7 to 10 liters of water per day per and men for man on long time doing strenuous physical work even upto 15 liters a day may be needed.
Salt intake must compensate for its excessive loss in sweating. Rest and sleep should be adequate as the recovery must compensate for the activity. he best period for the best satisfactory and result restful sleep is during the coolest 3 to 4 hrs before dawn.
Bathing should be done every day. Improved shower baths are also of great important and valuable. An active , healthy and clean skin is an important factor dissipation of heat through radiation and evaporation and convection.
Clothing should be normally light and loose and permeable to water vapour and air. Food must be wholesome and well cooked and must be consumed with good amount of fluid. Dining hall should be cool and comfortable as no one can be expected to take full meals under hot and humid conditions.
Living rooms must be well ventilated and cool. A large numbers of heat stroke cases occurs in congested and ill ventilated and crowded rooms and huts, etc. In an area if possible, fans made be available to workers in their tents and quarters and no one should be allowed to sleep out side.
Medical inspection should be regular and through to detect early symptoms of the heat effect or any other diseases which may aggravate the effects of heat. Cases detected early can be often placed in rest in a cool place.
Avoid working in sun when it is too hot from 1 p m to 3 pm(IST) and drink plenty of pure water and use umber la while walking in sun, also avoid tea,coffee and alcohol,etc. during extreme summer and take rest or avoid doing strenuous work during peak hours.
First aid and early treatment
Keep the patient in bed or on the floor and fan on to reduce temperature. Raise the foot end and keep wet cloths on the body to reduce temperature and give plenty of fluid diet. This is necessary to stop the progress of illness, avoid permanent neurological injury and save life. Temperature must be reduced rapidly by spraying cool water and fanning. Ice-cool water is not to be used. Give plenty of cool water to drink, not too much. The temperature is checked every 10 minutes when cooling is reduced when it comes to 39 degree centigrade, patient is to be removed to the heat stroke centre. Dehydration is treated by administration of fluids and electrolytes. Cases of pure water loss is treated with water only. In severe cases with considerable impairment of mental and physical capacity there may be a deficit of 5 to 10 liters. In salt deficiency, if there is any giddiness and fainting on standing, there may be an approximate deficit of 4liters isotonic saline and if urinary chlorides are absent and if there is any feeling of vomiting/anorexia, nausea and vomiting with systolic blood pressure above 90mm of mercury, there may be a deficit of 5 liters, and if systolic blood pressure is less than 90mm of mercury, there is an approximate deficit of 8 liters.
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